Electrical circuit carriers with small dimensions, especially integrated circuit (IC) components are generally assembled or cast by the manufacturer by reason of their sensitive structure and their small dimensions; the fine, sensitive connective wires are joined with contact feet formed on the circuit carrier. They come on the market in this form, in which for example the sensitive IC components themselves are no longer accessible from the outside. The shapes of the circuits, especially their dimensions, the number and spacing distance of their contact feet, etc., are largely standardized.
The circuit carrier can then be plugged into receptacles formed on the electrical appliance which are arranged in contact feet, where it comes into connection with the elements of an electrical circuit with which it is to interact. The contact feet are generally soldered with the connecting piece.
In order to make easier this very laborious assembling, which by reason of the soldering heat formed is especially disadvantageous for the IC components, the principle has already been known of first placing a base on the electrical applicance, which base is provided with contact elements corresponding to the contact feet of the circuit carrier so that it fits in the receptacles of the appliance. Since the base does not carry any sensitive electronic components, it can be soldered without danger to the connecting piece. An IC carrier for example is placed on this base, whereby these contact feet come into connection with the contact elements of the base. In order to protect the IC carrier as well as to hold the latter fast onto the base, a cover is provided which can be clapped on over the IC carrier (AMP prospectus, "Interconnection Packaging Devices and Accessories", 1974, No. 14, pages 120 and 121).
In the known solution the assembling and particularly the assembling by hand of the whole apparatus is very complicated and involves uncertainties as regards the correct arrangement of the IC carrier. The IC carriers in general are constructed symmetrically with respect to a longitudinal axis. Therefore they can basically be used in two positions rotated by 180.degree. in receptacles formed in the electrical appliance. The correct position can be recognized only from a marking or the like arranged on the IC carrier. Likewise, in the known solution the IC carriers can be placed on the base in two different positions rotated by 180.degree., when special coding means are not arranged both on the base and on the IC carrier, which permit only one mounting position of the IC carrier on the base. However such coding means are not provided on the standardized IC carriers.
For assembling the apparatus, the IC carrier is first placed on the base which has previously been connected with the electrical appliance, wherewith the correct position of the IC carrier is not ensured, especially when the mounting places are not easily accessible or visible. The IC carrier must then be pressed onto the flexible contact elements of the base and secured on these, while the cover is being clapped on over the IC carrier and placed on the base, which requires quite a special aptitude on the workers especially when the mounting places are not very accessible.